Thread tensioning and take-up device



July 30, 1957 J. S. KARL THREAD TENSIONING AND TAKE-UP DEVICE Filed Nov. 4, 1955 nite Sttes Patent THREAD TENSlU-NENG AND TAKE-UP DEVICE Josef S. Karl, Athens, Ga.

Application November 4, 1955, Serial No. 544,920

6 Claims. (Cl. 66-125) The present invention relates to a thread tensioning and take-up device which permissibly may also be used for moistening, treating, or lubricating.

The present application is a continuation-in-part of my copending application Serial No. 477,263, filed December 23, 1954, for Thread Tensioning and Take-up Device, now abandoned.

A purpose of the invention is to provide a more responsive thread tensioning and take-up device which will give uniformity of tension and freedom from undesired loops, so as to eliminate or minimize difiiculties encountered in knitting, such as fish-eyes, press-offs, uneven selvages and non-uniform lengths of goods, especially hosiery.

A further purpose is to facilitate starting after a period of shut-down by eliminating soilage and gumming of Snappers or other spring tensioning devices, to avoid the necessity of pulling up to obtain uniform starting tension on thread ends.

A further purpose is to reduce wear and tear on thread carriers and tubes due to erratic operation of tensioning devices.

A further purpose is to facilitate the change of tensioning weighting elements with change in denier of the thread or yarn.

A further purpose is to accomplish the tensioning of thread passing between opposed guides over a central support, which may permissibly be a wick, or may be a supplemental guide, by applying the tensioning effect of levers resting on the top of the yarn, one on one side and the other on the other side of thesupport, and desirably both pivoted rearwardly of the point of engagement of the yarn when considered in thedirection of thread motion, and desirably also pivoted 01f and preferably above the direct line between the opposed guides.

A further purpose is to make the forwardrnost of the guides and preferably both of the. guides assume a taut position which is close to and under normal operating conditions within 45 of the horizontal, so that with take-up incident to change in the rate of feed the weight of the lever will accomplish the take-up with relatively gradual change of the effective torque at a position at which the cosine of the angle between the horizontal and the line connecting the pivot and the point of engagement of the lever with the yarn is changing rather gradually.

A further purpose is to provide a range of take-up over which the forward arm particularly and permissibly also the rearward arm can swing down as the thread becomes slack which will extend over at least 45 below the taut position.

A further purpose is to make the forwardmost lever relatively longer than the rearwardmost lever.

A further purpose is to provide angular bends in the sides of the lever to increase the effective weight due to the wire alone.

A further purpose is to permit convenient change of levers by simply springing out one U-shaped wire element from the pivot holes and inserting another at each lever position.

A further purpose is to extend the thread in a straight line through the opening in the wick between the thread guides.

Further purposes appear in the specification and in the claims.

In the drawings 1 have chosen to illustrate a few only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoints of satisfactory operation, convenience in illustration and clear demonstration of the principles involved.

Describing in illustration but not in limitation and referring to the drawings:

Figure l is a central vertical section through a thread tensioning take-up, moistening, lubricating and treating device according to the invention.

Figure 2 is a section of Figure l on the line 2-2.

Figure 3 is a fragmentary section corresponding to Figure 1 showing the levers in take-up position.

Figure 3 is a view corresponding to Figure 3 showing a variation.

Figure 4 is a fragmentary perspective showing a variation in which the cross arm at the base of the U lever is concave.

Figure 5 is a fragmentary perspective showing a variation in wire size.

Figure 6 is a fragmentary perspective showing a variation.

In the prior art, extensive use has been made of springs or snappers for thread tensioning on knitting machines and also on sewing machines and other devices. These devices are subject to several disadvantages. In the first place the control of tension and take-up is often relatively non-uniform so that small unintentional loops can occur in the feed. The non-uniformity of the feed and the presence of loops at the end of a stroke are particularly objectionable in the knitting of hosiery where they lead to a number of difiiculties causing rejection of the product. In some cases abnormal loops cause thread distortion in the knitted product, producing defects known as fish eyes.

Another difiiculty is that the needles miss, producing press-offs and in some cases cut holes. The effect of the non-uniformity also is to make the selvage uneven so that when the seam is completed the seam tends to be irregular in full-fashioned hosiery. The accumulated eflect of the unevenness of feed makes itself apparent also in nonuniform length of the completed hosiery, making it difficult to knit for a predetermined size.

The snappers also tend to collect dirt and gum, and require relatively frequent cleaning and adjusting.

I have discovered that a great improvement can be obtained in yarn tensioning and take-up, eliminating entirely the spring tensioning, and applying an improved type of tensioning lever. The device of the invention is applicable for tensioning purposes, independently of moistening, but I find that it can very advantageously be applied to a conventional wick type of moistening device which is extensively used for sizing, moistening, lubricating and otherwise treating the thread with liquid.

My improved tensioning and take-up device, whether used alone or in connection with a conditioner, greatly improves the above ditiiculties which are attributable to unevenness in tensioning. Fish eyes in hosiery are reduced at least one-half by the device of the invention. Press-olts and cut holes in hosiery are diminished greatly. Obvious differences in the straightness of the selvage have largely disappeared where the device of the invention has been used. The length of the knitted product has been rendered more uniform. Due to the fact that no cleaning of gum on snappers is required and no pulling of ends is necessary, starting up after shutdown is rendered much easier.

The invention also reduces the labor required in caring for snappers and rings.

A more continuous production is obtained, and wear on carriers and tubes is correspondingly reduced.

The invention-is applicable over a wide variety of thread size and in knitting thread canbe applied over ranges of 12 to 70 denier or wider by simply modifying the efiective weight through changing the size or weight of the wire used for the lever.

The invention is by no means limited'in its application, and can be used on sewing machines or other equipment where tensioning is required. It is, however, believed to have its best application on full-fashioned hosiery knitting machines.

One of the great advantages of the device in connection with knitting machines is that due to the fact that the forward tensioning lever operates over a range at which the cosine of the angle with respect to the horizontal is changed gradually there can be take-up with only slight decrease in tension.

The working parts of the device do not have the tendency to accumulate gum or other dirt which has been true of snappers, and no difliculty through high startingfriction due to this ,dirt is to be encountered after a shut-down.

Considering now the device of the drawings in detail, I illustrate a thread moistener having a container 20 provided with a cap 21, secured by threads or other suitable means, the cap having an opening 22 in thecenter through which extends a Wick 23 of felt or the like. The wick extends down into a liquid contained in the bottle, which may be a lubricant, moistening solution, size or other treating liquid. The wick is guided by a clamp 24 having opposite prongs 25 which are secured together at the edges by bolts 26. A bracket 27 mounted on the cap extends upwardly and supports an inlet thread guide or eyelet 28 and an opposed outlet thread guide or eyelet 30 on opposite sides of the bracket. The eyelets have exterior flanges 31 and pass through openings 32 in the bracket. At the inside the eyelets are desirably provided with latching recesses 33 which are engaged by the ends of a latching spring 34 secured to the bracket at the center asby a bolt 35. The spring and bolt are broken away at the center in Figure l, and omitted in other figures. The eyelets are desirably placed at the same level opposite the upwardly extending portion of the wick.

Thread 36 enters the eyelet 28 and may be carried through a hole 37 in the wick substantially on the same level as the center line of the eyelets so that tension does not tend to relatively bind the thread against the moistening support due to a lateral component of the tensioning force (Figure 3). In some cases it may be preferable to carry the thread 36 over the top of the wick at 37' (Figure 3), instead of carrying the thread through a hole in the wick. In either Figure 3'or Figure 3, the thread at the other side of the wick passes through the central opening of eyelet 30 and passes to the knitting machine, sewing machine, or other equipment at 38.

The bracket at the top carries a series of pivot openings- 40, 41, 42 and 43 extending entirely across and providing selective pivot positions for weighting levers 44 and 45 respectively. The forward weighting lever 45 like the rearward lever desirably consists of a base or cross bar portion 46 which rests on top of the thread, permitting some lateral movement of the thread so as to distribute wear, side arm portions 47 on opposite sides, and initially bent pivotal ends 48 which engage a pivot in the pivot opening 42 or any other selected pivot opening.

The weighting lever is desirably made by bending wire of appropriate size, and in order to obtain the correct weight it will be desirable to substitute a U-shaped lever of larger or smaller diameter wire in some cases. Since the pivots are held in place merely by the spring of the wire, it is very easy to snap them out of place and substitute-other spring wire elements. The wire sizes which have been found convenient will vary with the operation being performed, but for the purpose of illustration and not limitation it can be stated that in connection with a full-fashioned hosiery machine of the usual Textile Machine Company type, No. 10 steel wire has been suitable for both weighting levers for 40 denier multi-filament thread. No. 18 steel wire has been used on the weighting levers for 15 denier monofilarnent yarn. Heavier wire than No. 10 can be used for ranges up to 70 denier. The removability of the wire loops and their relative freedom in the pivot holes tends to prevent them from clogging and sticking on account of dirt or gum.

In many cases the weight obtainable from a convenient size of wire is not exactly suitable and angle bends are provided at 50 in the side lever elements, thus increasing the weight which is effective against the yarn. These angle bends can be adjusted to make them steeper or straighter, to make minor variations in effective weight.

In the preferred embodiment, both of the weighting levers are pivoted rearwardly considering the direction of thread motion with respect to the positions at which they engage the thread. The pivot point is also preferably not in the direct line of the thread motion but displaced therefrom and desirably above the direct line as shown. The fact that the weighting levers are pivoted rearwardly and above means that as the yarn becomes taut they tend to move into the straight yarn path, thus reducing wear on the levers and reducing the tendency to abrade the yarn.

When the knitting machine comes to the end of its stroke and a small loop might otherwise form, with danger of causing a defect in the hosiery or other work, the slack is taken up by movement of the weighting levers relatively counterclockwise in Figure 1 so that the points of engagement on the top of the yarn at 51 and 52 in Figure 1 change to points of engagement at 51' and 52' in Figure 3. ,As the slackness disperses and the thread becomes taut, the weighting levers move in the clockwise direction in Figure 1 until in the extreme taut position the thread extends straight across between the guides and through the wick or other central support (which may be employed when moistening is not used), and the weightinglevers merely rest on the top of the yarn and impart drag.

An important aspect of the invention is that the forward weighting lever 45 particularly, which accomplishes most of the take-up, and the rearward weighting lever secondarily which accomplishes a less important part of the take-up, operate in taut position as shown in dot-anddash lines in Figure 1 at a position in which the line 53 extending from the pivot to the point at which the weighting lever rests on the arm is not more than 45 below the horizontal, sothat the cosine of the angle will change relatively little with increase in this angle as take-up is accomplished.

Thus there will be relatively little decrease in the effective weight of the weighting lever as it accomplishes take-up especially in the relatively short lengths of take-up which most commonly occur. There is a considerable angular range of take-up permitted for both levers and particularly for the forward weighting lever, not less than 45 assuring that longer lengths of slack will be adequately taken care of by take-up. Furthermore it will be evident that the forward weighting lever 45 is considerably longer than the rearward weighting lever, so that there is a very considerable range of motion provided for the forward weighting lever for take-up purposes.

In the embodiment shown in Figure 4, the lower bar or base portion 46 is concave at 46 in both of the weighting levers, thus increasing the tendency to maintain the yarn relatively central, without at the same time confining the yarn to a limited path as would be the case if an eyelet were used. The threading of the thread through the device is very easily accomplished, any suitable needle or tool being used to form the hole 37 in the wick and carry the thread through the wick between the eyelets 28 and 30.

Once the device is adequately threaded and the thread carried to the operating mechanism, the levers swing automatically, depending on the amount of slack available, moving clockwise in Figure 1 as the thread becomes taut and moving counterclockwise in Figure l as take-up occurs. This is particularly true of the forward weighting lever which mainly accomplishes take-up, the rear weighting lever acting more as an equalizer. The selection of different pivot holes at the top of the bracket permits using longer or shorter weighting levers to suit the desired wire sizes and over-all weights of different deniers, substitutions being made simply by snapping one set of weighting levers out of their pivot holes and inserting a new set in the same pivot holes or in adjacent pivot holes as required.

If conditions are not exactly right at assembly, the wires are easily bent to change the angles of the side portions to slightly increase or decrease the effective weight.

In some cases where liquid treatment of the thread is not desired, the wick may be eliminated, and a support, suitably an inverted U-shape wire 53 will be mounted on the bolts 26 as shown in Figure 6, providing at the top of the U a concave guiding wire portion 54 over which a thread extends between engagement with the levers 44 and 45. The operation of the levers will be the same as in the other forms.

In view of my invention and disclosure, variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I therefore claim all such insofar as they fall within the reasonable spirit and scope of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a thread tensioning and take-up device, a pair of opposed thread guides, a thread suppoorting surface intermediate between the guides, a pair of thread tensioning levers, each pivotally supported at a position located rearwardly with respect to the direction of thread motion and above the thread, each of the levers extending across and engaging the top of the thread at a position forward of the pivot of the respective lever one on one side and the other on the other side of the central supporting surface, the lever which engages the thread forward of the supporting surface having a depending position at which yarn take-up occurs and a taut position at which the yarn is tight and the lever relatively raised, and the line between the lever portion engaging the thread and the lever pivot being at an angle within 45 of the horizontal and being capable of depending below the taut position over an angular range of movement of at least 45.

2. A device according to claim 1, in which the arm which engages the thread forward of the support is longer than the arm which engages the thread rearwardly of the support.

3. A device according to claim 1, in which the levers are angularly bent at the sides.

4. A device according to claim 1, in which the levers have thread engaging portions which are concave.

5. A device for tensioning and take-up of yarn, comprising opposed guides, a wick positioned between the guides and adapted to engage thread passing between the guides, and tensioning levers pivotally mounted off of the direct line of yarn travel between the guides and rearward in the direction of yarn travel with respect to the point of engagement of the lever with the yarn, the levers engaging the top of the thread on opposite sides of the wick, the forwardmost lever considered in the direction of thread travel having a taut position and a yarn take-up range, the taut position bringing the line connecting the lever pivot with the point of engagement of the lever with the thread within 45 of the horizontal and the take-up extending over an angular range of at least 45 below the taut position.

6. A thread tensioning and take-up device, comprising opposed thread guides, a wick positioned between the guides adapted to engage thread passing between the guides, and yarn tensioning levers one engaging the top of the thread on each side of the wick, each pivoted at a position transverse to the straight path of the thread between the guides on a pivot point located rearwardly of the point of engagement with the thread, considered in the direction of thread motion, the lever which engages the thread forwardly of the wick having a taut position and a take-up position, the taut position bringing the line between the pivot and the point of engagement with the thread within 45 degrees of the horizontal and the take-up position permitting a range of motion of the forward lever of not less than 45 degrees below the taut position.

References Cited in the file of this patent UNITED STATES PATENTS 1,960,670 Friedmann May 29, 1934 2,566,005 Ward Aug. 28, 1951 2,630,982 Gagas Mar. 10, 1953 

